1. Field of the Invention
The present invention relates to a vehicle automatic operation control device comprising a target required torque calculating part which determines the target required torque from the respective calculated values according to the feed-forward calculated value based on the target acceleration and the feedback calculated value based on the deviation between the target acceleration and the actual acceleration, and an automatic operation control part which causes automatic operation of the vehicle on the basis of the determined target required torque.
2. Description of the Related Art
In the above vehicle automatic operation control device, a feed-forward calculated value is determined on the basis of the target acceleration by feed-forward calculations, and the feedback calculated value is determined on the basis of the deviation between the target acceleration and actual acceleration by feedback calculations. Furthermore, the target required torque is determined from the respective calculated values of the feed-forward calculated value and feedback calculated value, and the vehicle is automatically operated by repeating in real time an operation that applies this target required torque to the vehicle. Here, the target required torque refers to the braking torque that is applied to the wheels during deceleration, or the driving torque that is applied to the drive wheels during acceleration.
In the automatic operation control, for example, when the vehicle is automatically operated on a road surface with a low coefficient of friction, the target required torque may become excessively large and the wheels may slip if the target acceleration is large. Accordingly, the automatic operation control part performs slip suppression control, and a slip suppressing torque is applied to the vehicle. Types of slip suppression control include ABS control that suppresses slip of the wheels during deceleration of the vehicle, and traction control that suppresses slip of the wheels during acceleration of the vehicle.
During automatic operation, a slip suppressing torque is applied to the vehicle with preference over the target required torque when slip suppression control is performed. For example, a slip suppressing torque is preferentially applied to the vehicle by disposing the location where the slip suppressing torque is applied by ABS control downstream from the location where the target required torque is applied.
Thus, during the performance of slip suppression control, the target required torque is not applied to the vehicle, and the actual acceleration cannot track the target acceleration. For this reason, a large deviation is generated between the target acceleration and actual acceleration, and the feedback calculated value becomes excessive. On the other hand, slip of the wheels does not occur, and when the slip suppression control is completed, the target required torque determined from the respective calculated values of the feed-forward calculated value and feedback calculated value is applied to the vehicle. Accordingly, when the target required torque is determined from the respective calculated values of the feed-forward calculated value and feedback calculated value during the performance of slip suppression control, an excessive target required torque is applied to the vehicle when the slip suppression control is completed; an abrupt acceleration and abrupt deceleration are therefore generated, and the operating state of the vehicle becomes unstable.
Accordingly, conventional vehicle automatic operation control devices include devices which are devised so that when, for example, ABS control is performed as slip suppression control, the target required torque calculating part maintains the target required torque at a constant value. In this technique, when the slip suppression control is completed, the target required torque maintained at a constant value is applied to the vehicle; accordingly, there is no application of an excessively large target required torque to the vehicle, and the operating state of the vehicle can be prevented from becoming unstable (for example, see Patent Document 1).
[Patent Document 1] JP (Kokai) 6-1229